What are the hotkeys to navigate the timeline?
→ 1 frame forward
← 1 frame backward

Shift+→ end frame
Shift+← start frame

↑ next keyframe  
↓ previous keyframe  

&#9096; Ctrl&#8679; Shift&#8594; next marker
&#9096; Ctrl&#8679; Shift&#8592;  previous marker  

Shift+↑ 10 frames forward
Shift+↓ 10 frames back